Detecting a small perturbation through its non-Gaussianity

By Lotfi Boubekeur, D. Lyth. 2005

198 citations recorded by the source corpus.

A highly non-Gaussian cosmological perturbation with a flat spectrum has unusual stochastic properties. We show that they depend on the size of the box within which the perturbation is defined, but that for a typical observer the parameters defining the perturbation 'run' to compensate for any change in the box size. Focusing on the primordial curvature perturbation, we show that an uncorrelated Gaussian-squared component is bounded at around the 10% level by the Wilkinson Microwave Anisotropy Probe (WMAP) bound on the bispectrum, and we show that a competitive bound may follow from the trispectrum when it too is bounded by WMAP. Similar considerations apply to a highly non-Gaussian isocurvature perturbation.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/0d80e25f2dbec20b6cafe9347ac94d3d66502003

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Citations in the corpus

Inflationary trispectrum from graviton exchange (2008, background): “Indeed, several authors [23, 5, 24] have used a momentum dependent τNL alone to parametrize the full trispectrum.”
PRIMORDIAL NON-GAUSSIANITY, SCALE-DEPENDENT BIAS, AND THE BISPECTRUM OF GALAXIES (2009, background): “Recently, a number of groups (e.g., Boubekeur & Lyth 2006; Huang & Shiu 2006; Byrnes et al. 2006; Buchbinder et al. 2008) have shown that the primordial trispectrum can in general be written as TΦ(k1, k2, k3, k4) =6gNL [Pφ(k1)Pφ(k2)Pφ(k3) + (3 cyclic)] + 25 18 τNL × [Pφ(k1)Pφ(k2) {Pφ(k13) +…”
Primordial non-Gaussianities from multiple-field inflation (2005, unknown): “The three-point function in multiple-field models . . . . . . . . . . . . . . . 8”
Primordial black holes in non-Gaussian regimes (2013, unknown): “The variance of ζ is then given by [39, 40] Pζ = σ(2) + 4 ( 3fNL 5 )2 σ(4) ln(kL), (16)”
Infrared effects in inflationary correlation functions (2010, background): “The argument of Boubekeur and Lyth [49], which was extended to two loops by Bartolo et al [84], shows that physical observables compose correctly under the process of averaging L-sized boxes to make an L′-sized box.”
Cosmology and Fundamental Physics with the Euclid Satellite (2012, background): “Interestingly, curvaton fluctuations could be negligible in the 2-point function but detectable through their non-Gaussian signature in the 3-point function, as studied in [215].”